Electromagnetic current-limiter.



T. GUDEM.

ELECTROMAGNETIC CURRENT LIMITER.

APPLICATION FILED MAR. 2!. ma.

1,302,916, Patented May 6,1919.

In van for 75 Me Gzza'em PATENT OFFICE.

TRYGVE GUDEM, OF CHRISTIANIA, NORWAY.

ELECTROMAGNETIC CURRENT-LIMITER.

Specification of Letters Patent.

Patented May 6, 1919.

Application filed March 27, 1918. Serial No. 225,114.

- To all whom it may concern:

Be it known that I, TRYGVE GUDEM, a subject of the King of Norway, residing at Ohristiania, in the Kingdom of Norway, have invented certain new and useful Improvements in Electromagnetic Current- Limiters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to electromagnetic current limiters and has for its object a device for taking up and equalizing the current shock which is caused by the cutting in of the current after an interruption of the same, owing to the decreased resistance of the metal filaments in electric lamps, at low temperatures.

This object is attained according to the present invention by means of two magnet coils with separated cores, said cores being so disposed with regard to a pivoted lever of magnetic material that the same forms a magnetic connection between the cores in the normal position of the current limiter. Said lever is however removed from the magnet cores by means of the relay-armature, when the same is attracted by the magnets, and is connected in such a manner with a movable main current contact, that the current is cut in or out in a position when the lever has been removed a certain distance from the magnet cores and interrupted the magnetic connection between the same.

At the moment in which the current is again out in the action of the magnet will then be weaker than in the normal position of the parts of the current limiter, as the two magnet cores are not yet magnetically connected, so that the current limiter can take up a larger load in the moment of cutting in than under the usual conditions.

On the drawing is diagrammatically illustrated a form of the invention.

1 and 2 are the current transmission wires, one wire of which is directly connected with the consumption wire 3 by means of contact piece 4.

From the other wire 2 the current passes to electromagnet 5 and from there is conducted to the point of pivot 6 for the pivoted lever 7, which is normally by means of contacts 8, 9 connected with the second consumption wire.

The contact piece 9, as will be seen, is slideably mounted in a holder 11, so that it follows contact 8 some distance before the current is interrupted. Thus the contact between 8 and 9 is closed before arm 7 regains its normal position. Contact piece 9 is preferably actuated by a spring or similar device acting to press it in the direction of contact 8.

Lever 7 on the opposite side of its pivot forms a bridge between cores 16 for electromagnet 5 and connects said cores magnetically. This magnetic connection is interrupted when the lever is brought out of its position. Preferably lever 7 is so mounted that it does not quite touch cores 16, and since the latter exert a continual attraction upon the lever it maintains good contact between members 8, 9. The armature 13 of the magnet on its free end carries a hammer 14 located below a similar hammer 15 on the free end of lever 7. When the armature 13 is attracted by the magnet in the usual manner owing to an overload, hammer 14 strikes hammer 15, so that arm 7 is swung out of its position interrupting contact 8, 9, after the contact 9 has followed contact 8 part of the way.

When the lever 7 owing to the weight of hammer 15 returns to its original position, contact 8 is closed before arm 7 has estab- .lished the magnetic connection between cores 16, and the action of the same on arm 13 is therefore weaker in the moment of cutting in than after the arm 7 has regained its normal position.

I claim:

1. In an electromagnetic current limiter a main current magnet comprising two separated cores, an armature for said main current magnet, said armature being adapted to be attracted by the magnet at a certain load, a main current contact comprising a pivoted lever forming normally a magnetic connection between the two separated cores of the magnet, said lever being adapted to be swung out of its position by means of said armature when the latter is attracted by its magnet, thereby interrupting the main current contact, said main current contact being so constructed that it is maintained in closed position until said lever has been removed a predetermined disbe swung out of its :positionrby-means of said armature when the latter is attracted by its magnet, :thereby interrupting Zthe main current Contact, said main current con tact comprislng a yleldingly supported con- "tact member Which-is adapted to follow the pivoted leverrand maintain contact with the same until said lever has been removed a predetermined dlstance from the magnet cores, andhas interrupted the magnetlc con- :nection between the same.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

TRYGVE GUDEM.

"Vitnesses 1H. FK. iHILE, ER. GARDENTER.

flopies ofithis i-patenc may be obtained toning-cents each, ;by.-ra.ddressing th,e Gommissioner of ilfiatents,

Washington, 113m! 

